Merge #7061: [Wallet] Add RPC call "rescanblockchain <startheight> <stopheight>"

7a91ceb5e [QA] Add RPC based rescan test (Jonas Schnelli)
c77170fbd [Wallet] add rescanblockchain <start_height> <stop_height> RPC command (Jonas Schnelli)

Pull request description:

  A RPC rescan command is much more flexible for the following reasons:
  * You can define the start and end-height
  * It can be called during runtime
  * It can work in multiwallet environment

Tree-SHA512: df67177bad6ad1d08e5a621f095564524fa3eb87204c2048ef7265e77013e4b1b29f991708f807002329a507a254f35e79a4ed28a2d18d4b3da7a75d57ce0ea5

4 files changed, 94 insertions, 7 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 5d98498a4b..e23ef57db0 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -3212,6 +3212,81 @@ UniValue generate(const JSONRPCRequest& request)
     return generateBlocks(coinbase_script, num_generate, max_tries, true);
 }
 
+UniValue rescanblockchain(const JSONRPCRequest& request)
+{
+    CWallet * const pwallet = GetWalletForJSONRPCRequest(request);
+    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
+        return NullUniValue;
+    }
+
+    if (request.fHelp || request.params.size() > 2) {
+        throw std::runtime_error(
+            "rescanblockchain (\"start_height\") (\"stop_height\")\n"
+            "\nRescan the local blockchain for wallet related transactions.\n"
+            "\nArguments:\n"
+            "1. \"start_height\"    (numeric, optional) block height where the rescan should start\n"
+            "2. \"stop_height\"     (numeric, optional) the last block height that should be scanned\n"
+            "\nResult:\n"
+            "{\n"
+            "  \"start_height\"     (numeric) The block height where the rescan has started. If omitted, rescan started from the genesis block.\n"
+            "  \"stop_height\"      (numeric) The height of the last rescanned block. If omitted, rescan stopped at the chain tip.\n"
+            "}\n"
+            "\nExamples:\n"
+            + HelpExampleCli("rescanblockchain", "100000 120000")
+            + HelpExampleRpc("rescanblockchain", "100000 120000")
+            );
+    }
+
+    LOCK2(cs_main, pwallet->cs_wallet);
+
+    CBlockIndex *pindexStart = chainActive.Genesis();
+    CBlockIndex *pindexStop = nullptr;
+    if (!request.params[0].isNull()) {
+        pindexStart = chainActive[request.params[0].get_int()];
+        if (!pindexStart) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid start_height");
+        }
+    }
+
+    if (!request.params[1].isNull()) {
+        pindexStop = chainActive[request.params[1].get_int()];
+        if (!pindexStop) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid stop_height");
+        }
+        else if (pindexStop->nHeight < pindexStart->nHeight) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "stop_height must be greater then start_height");
+        }
+    }
+
+    // We can't rescan beyond non-pruned blocks, stop and throw an error
+    if (fPruneMode) {
+        CBlockIndex *block = pindexStop ? pindexStop : chainActive.Tip();
+        while (block && block->nHeight >= pindexStart->nHeight) {
+            if (!(block->nStatus & BLOCK_HAVE_DATA)) {
+                throw JSONRPCError(RPC_MISC_ERROR, "Can't rescan beyond pruned data. Use RPC call getblockchaininfo to determine your pruned height.");
+            }
+            block = block->pprev;
+        }
+    }
+
+    CBlockIndex *stopBlock = pwallet->ScanForWalletTransactions(pindexStart, pindexStop, true);
+    if (!stopBlock) {
+        if (pwallet->IsAbortingRescan()) {
+            throw JSONRPCError(RPC_MISC_ERROR, "Rescan aborted.");
+        }
+        // if we got a nullptr returned, ScanForWalletTransactions did rescan up to the requested stopindex
+        stopBlock = pindexStop ? pindexStop : chainActive.Tip();
+    }
+    else {
+        throw JSONRPCError(RPC_MISC_ERROR, "Rescan failed. Potentially corrupted data files.");
+    }
+
+    UniValue response(UniValue::VOBJ);
+    response.pushKV("start_height", pindexStart->nHeight);
+    response.pushKV("stop_height", stopBlock->nHeight);
+    return response;
+}
+
 extern UniValue abortrescan(const JSONRPCRequest& request); // in rpcdump.cpp
 extern UniValue dumpprivkey(const JSONRPCRequest& request); // in rpcdump.cpp
 extern UniValue importprivkey(const JSONRPCRequest& request);
@@ -3222,6 +3297,7 @@ extern UniValue importwallet(const JSONRPCRequest& request);
 extern UniValue importprunedfunds(const JSONRPCRequest& request);
 extern UniValue removeprunedfunds(const JSONRPCRequest& request);
 extern UniValue importmulti(const JSONRPCRequest& request);
+extern UniValue rescanblockchain(const JSONRPCRequest& request);
 
 static const CRPCCommand commands[] =
 { //  category              name                        actor (function)           argNames
@@ -3276,6 +3352,7 @@ static const CRPCCommand commands[] =
     { "wallet",             "walletpassphrasechange",   &walletpassphrasechange,   {"oldpassphrase","newpassphrase"} },
     { "wallet",             "walletpassphrase",         &walletpassphrase,         {"passphrase","timeout"} },
     { "wallet",             "removeprunedfunds",        &removeprunedfunds,        {"txid"} },
+    { "wallet",             "rescanblockchain",         &rescanblockchain,         {"start_height", "stop_height"} },
 
     { "generating",         "generate",                 &generate,                 {"nblocks","maxtries"} },
 };
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 5ebacd57d3..2b12168c65 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -386,7 +386,7 @@ BOOST_FIXTURE_TEST_CASE(rescan, TestChain100Setup)
     {
         CWallet wallet;
         AddKey(wallet, coinbaseKey);
-        BOOST_CHECK_EQUAL(nullBlock, wallet.ScanForWalletTransactions(oldTip));
+        BOOST_CHECK_EQUAL(nullBlock, wallet.ScanForWalletTransactions(oldTip, nullptr));
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 100 * COIN);
     }
 
@@ -399,7 +399,7 @@ BOOST_FIXTURE_TEST_CASE(rescan, TestChain100Setup)
     {
         CWallet wallet;
         AddKey(wallet, coinbaseKey);
-        BOOST_CHECK_EQUAL(oldTip, wallet.ScanForWalletTransactions(oldTip));
+        BOOST_CHECK_EQUAL(oldTip, wallet.ScanForWalletTransactions(oldTip, nullptr));
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 50 * COIN);
     }
 
@@ -604,7 +604,7 @@ public:
         bool firstRun;
         wallet->LoadWallet(firstRun);
         AddKey(*wallet, coinbaseKey);
-        wallet->ScanForWalletTransactions(chainActive.Genesis());
+        wallet->ScanForWalletTransactions(chainActive.Genesis(), nullptr);
     }
 
     ~ListCoinsTestingSetup()
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 50c1375f44..3672ecea5b 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1568,7 +1568,7 @@ int64_t CWallet::RescanFromTime(int64_t startTime, bool update)
     LogPrintf("%s: Rescanning last %i blocks\n", __func__, startBlock ? chainActive.Height() - startBlock->nHeight + 1 : 0);
 
     if (startBlock) {
-        const CBlockIndex* const failedBlock = ScanForWalletTransactions(startBlock, update);
+        const CBlockIndex* const failedBlock = ScanForWalletTransactions(startBlock, nullptr, update);
         if (failedBlock) {
             return failedBlock->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1;
         }
@@ -1584,12 +1584,19 @@ int64_t CWallet::RescanFromTime(int64_t startTime, bool update)
  * Returns null if scan was successful. Otherwise, if a complete rescan was not
  * possible (due to pruning or corruption), returns pointer to the most recent
  * block that could not be scanned.
+ *
+ * If pindexStop is not a nullptr, the scan will stop at the block-index
+ * defined by pindexStop
  */
-CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate)
+CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, CBlockIndex* pindexStop, bool fUpdate)
 {
     int64_t nNow = GetTime();
     const CChainParams& chainParams = Params();
 
+    if (pindexStop) {
+        assert(pindexStop->nHeight >= pindexStart->nHeight);
+    }
+
     CBlockIndex* pindex = pindexStart;
     CBlockIndex* ret = nullptr;
     {
@@ -1617,6 +1624,9 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool f
             } else {
                 ret = pindex;
             }
+            if (pindex == pindexStop) {
+                break;
+            }
             pindex = chainActive.Next(pindex);
         }
         if (pindex && fAbortRescan) {
@@ -3930,7 +3940,7 @@ CWallet* CWallet::CreateWalletFromFile(const std::string walletFile)
         }
 
         nStart = GetTimeMillis();
-        walletInstance->ScanForWalletTransactions(pindexRescan, true);
+        walletInstance->ScanForWalletTransactions(pindexRescan, nullptr, true);
         LogPrintf(" rescan      %15dms\n", GetTimeMillis() - nStart);
         walletInstance->SetBestChain(chainActive.GetLocator());
         walletInstance->dbw->IncrementUpdateCounter();
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index c4af192f36..8315bbf3da 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -919,7 +919,7 @@ public:
     void BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) override;
     bool AddToWalletIfInvolvingMe(const CTransactionRef& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate);
     int64_t RescanFromTime(int64_t startTime, bool update);
-    CBlockIndex* ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate = false);
+    CBlockIndex* ScanForWalletTransactions(CBlockIndex* pindexStart, CBlockIndex* pindexStop, bool fUpdate = false);
     void ReacceptWalletTransactions();
     void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) override;
     // ResendWalletTransactionsBefore may only be called if fBroadcastTransactions!